1. Technical Field
This invention generally relates to sunshades for vehicle windshields, and in particular it relates to a foldable vehicular windshield sunshade without accordion folds.
2. Background Art
Accordion folded vehicle windshield sunshades, generally made from corrugated cardboard, are quite commonly used to prevent sun damage to vehicle dashboards and reduce heating of the interior of a car by sun rays. The most popular version is simply a rectangular panel of cardboard having a longitudinal dimension approximately equal to the length of a windshield and a transverse dimension, or width, approximately equal to the width of the windshield. The rectangular panel is provided with transverse accordion folds by alternately and transversely creasing the interior and exterior surfaces of the rectangle. In use, the sunshade is unfolded and placed in the front windshield and held in place by the dashboard, rearview mirror, and/or the sun visors. The problem with the transverse accordion like folds is that the sunshade tends to separate from the windshield at the ends and/or the middle by sagging. This sagging and separation of the sunshade from the windshield allows sun rays to penetrate into the interior of the car which is very undesirable.
A similar vehicular sunshade is taught by YADEGAR, ET AL., U.S. Pat. No. 4,671,334 which teaches a foldable vehicular sunshade which is collapsible to a smaller state. This is accomplished by providing a longitudinal fold about which the transverse panels can be folded. Again, the sunshade tends to pull away from the windshield, allowing sun rays to penetrate to the interior of the car. An even more compact foldable windshield sunshade is taught by SIEGLER, U.S. Pat. No. 4,727,920 which teaches a sunshade having a plurality of both transverse and longitudinal folds which create a series of hinged planar parallelograms. The sunshade of Siegler can be folded into a very compact state but is even more prone to separating from the windshield and thereby allowing sun rays to penetrate to the interior of the car.
The problem with any vehicular sunshade having transverse folds is that it is difficult, if not impossible, to provide adequate support in the longitudinal direction to prevent the sunshade from pulling away from the windshield and allowing the sun rays to penetrate to the interior of the vehicle.
What is needed, is a foldable vehicular windshield sunshade which does not have transverse accordion like folds and is not prone to separation from the windshield.
It is therefore an object of the present invention to provide a foldable vehicular windshield sunshade having longitudinal folds which are designed to bias the sunshade against the windshield and prevent separation of the sunshade from the windshield.